Standalone java application that calls Db2

Question

Hi,
I am trying to use coherence in my standalone java
application that makes JDBC calls to Db2.
The sql statemet is like below:
select lastName,firstName from employee where empNo=2224;
In the application,I would read from the flat file say
200 account numbers and query the database.
If I have queried the database already with the given
account,I want to retreive from the cache.
I am having real trouble in getting this work with
coherence software.
Any psudo code in this regard will help me a lot.
Thanks
DJon

Answer 1

Hi Jon,
Thanks for the mail.I am struck in
implementing the coherence in the sample program.
any help in this regard is appreciated.
Thanks
DJon
Below is the sample program that works without coherence.go to db2 and get the information.
import java.sql.*;
import java.util.*;
public class DB2Client
static void printColumn(String in)
System.out.print(in);
System.out.print(" | ");
public static void main(String[] args)
Driver myDriver = null;
Connection myConnection = null;
try
myDriver =
(Driver)Class.forName("com.ibm.db2.jcc.DB2Driver").newInstance();
myConnection =
DriverManager.getConnection("jdbc:db2:sample","dujon","jeff");
PreparedStatement myStatement
= myConnection.prepareStatement("SELECT
empno,firstnme,lastname FROM employee where empno > ?");
myStatement.setString(1,"00");
ResultSet
myResults=myStatement.executeQuery();
while (myResults.next())
printColumn(myResults.getString("empno") + "");
printColumn(myResults.getString("firstnme") + "");
printColumn(myResults.getString("lastname"));
System.out.println();
} catch (Exception e)
e.printStackTrace();
} finally
try
if (myConnection != null)
myConnection.close();
} catch (Exception e)
Now,to implement the above sample with
coherence I have written 2 programs.
1. TangosolDB2Cache.java
2. TestDB2Cache.java
import com.tangosol.net.cache.CacheStore;
import com.tangosol.util.Base;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
* An example implementation of CacheStore
* interface.
* @author erm 2003.05.01
public class TangosolDB2Cache extends
Base implements CacheStore
// ----- constructors
* Constructs DBCacheStore for a given
database table.
* @param sTableName the db table name
public TangosolJDBCCache(String
sTableName)
m_sTableName = sTableName;
configureConnection();
     * Set up the DB connection.
     protected void configureConnection()
          try
Class.forName("com.ibm.db2.jcc.DB2Driver");
               m_con =
DriverManager.getConnection(DB_URL, DB_USERNAME, DB_PASSWORD);
               m_con.setAutoCommit(true);
          catch (Exception e)
               throw ensureRuntimeException(e,
"Connection failed");
     // ---- accessors
* Obtain the name of the table this
CacheStore is persisting to.
* @return the name of the table this
CacheStore is persisting to
public String getTableName()
return m_sTableName;
* Obtain the connection being used to
connect to the database.
* @return the connection used to
connect to the database
public Connection getConnection()
return m_con;
// ----- CacheStore Interface
* Return the value associated with the
specified key, or null if the
* key does not have an associated
value in the underlying store.
* @param oKey key whose associated
value is to be returned
* @return the value associated with
the specified key, or
* <tt>null</tt> if no value is
available for that key
public Object load(Object oKey)
Integer iKey = (Integer)key;
     return query("select
lastName,firstName from employee where empNo = " + iKey);
* Store the specified value under the
specific key in the underlying
* store. This method is intended to
support both key/value creation
* and value update for a specific key.
* @param oKey key to store the
value under
* @param oValue value to be stored
* @throws
UnsupportedOperationException if this implementation or the
* underlying store is
read-only
public void store(Object oKey, Object
oValue)
          mycacheTable(oKey,oValue);
public void erase(Object oKey)
     public void eraseAll(Collection
colKeys)
          throw new
UnsupportedOperationException();
     public Map loadAll(Collection colKeys)
          throw new
UnsupportedOperationException();
     public void storeAll(Map mapEntries)
          throw new
UnsupportedOperationException();
     // ----- data members
     Hashtable mycacheTable = new Hashtable(1000);
     * The connection.
     protected Connection m_con;
     * The db table name.
     protected String m_sTableName;
     * Driver class name.
     private static final String DB_DRIVER =
"org.gjt.mm.mysql.Driver";
     * Connection URL.
     private static final String DB_URL =
"jdbc:db2:sample";
     * User name.
     private static final String DB_USERNAME =
"dujon";
     * Password.
     private static final String DB_PASSWORD =
"jeff";
TESTING THE ABOVE PROGRAM
import com.tangosol.net.cache.CacheStore;
import com.tangosol.util.Base;
import
com.tangosol.net.cache.MapCacheStore;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
public class TestDB2Cache {
     public static void main(String args[]){
                    TangosolJDBCCache mycache = new
TangosolDB2Cache("employee");
                    Connection
con=mycache.configureConnection();
                    MapCacheStore cacheStuff = new
MapCacheStore(HashMap hmap);
                    String[] employeeNumbers =
{"000010","000020","000030","000040","000050"};
                              // find whether it has been cached already
                                   for(int
i=0;i<employeeNumbers.length();i++){
                                   oCurValue =
cacheStuff.load(employeeNumbers);
                                   if(oCurValue == null){
                                        // execute SQL statement
                                        con.executeQuery(oCurKey);
                                   else
                                        //get from cache the values and return
                                        cacheStuff.load(oCurKey);